The drug has also been prescribed as an appetite stimulant. (One of its most common side effects is weight gain.)

Mirtazapine was approved by the Food and Drug Administration (FDA) for use as an antidepressant in 1996. Its patent expired in 2004 and generic versions are now available.

Mirtazapine Warnings

Like many antidepressants, the FDA requires that mirtazapine carry a black-box warning because of an increased risk of suicide.

Before you start using mirtazapine, tell your doctor about your family's medical history, including any psychiatric disorders or history of suicide attempts.

If you are using mirtazapine, tell your doctor immediately if you notice worsening depression or other psychiatric conditions, or any unusual behavior changes, especially if you're younger than 25.

This includes possible suicidal thoughts, new or worsening anxiety, or panic attacks.

You should also tell your doctor if you have trouble sleeping, become easily irritated, or start taking impulsive actions.

Be especially watchful for these symptoms when this medication is started or when the dose is changed.

Your doctor also needs to be aware if you have liver or kidney disease, seizures of any kind, high cholesterol, heart disease, or if you have ever had a heart attack or stroke.

Mirtazapine and Sleep

Some doctors prescribe mirtazapine or other antidepressants to treat sleep disorders such as insomnia.

An August 2012 report in the Annals of Clinical Psychiatry noted that mirtazapine had proven sleep-promoting effects, and that use of the drug should "be balanced with mirtazapine's ability to cause sedation-related side effects."

Talk with your doctor about use of mirtazapine or other drugs to address sleep disorders.

Mirtazapine 'High' and Abuse

Anecdotal reports indicate that some people have used mirtazapine to "get high," largely due to its sedative effects.

Recreational use of this drug can result in severe side effects and death, especially when combined with alcohol or other drugs.

Take mirtazapine only as directed by your doctor, and keep this and all other drugs away from children, teenagers, and anyone for whom the drug has not been prescribed.

Mirtazapine Withdrawal

Don't stop the use of mirtazapine without first discussing it with your doctor.

If mirtazapine is discontinued abruptly, you could experience withdrawal symptoms such as dizziness, headache, nausea, and changes in mood.

You may experience withdrawal symptoms even if you miss just a few doses, so it's recommended that your dose of mirtazapine be reduced gradually when therapy is discontinued.

Pregnancy and Mirtazapine

There have been no significant studies of mirtazapine use by pregnant women, and it's not known if mirtazapine can be passed through a mother's breast milk to a breastfeeding baby.

Several studies have linked the use of antidepressants during pregnancy with a higher overall risk of stillbirth and newborn death.

Other, newer studies show that risk may not be warranted.

If you are pregnant or breastfeeding, you and your doctor should determine if the benefits of using mirtazapine outweigh the potential risks.

Mirtazapine for Cats and Dogs

Veterinarians may prescribe mirtazapine as an appetite stimulant, especially for cats and dogs that have a stomach condition, nausea, or other causes of a lack of appetite.

Drowsiness is the most common side effect of mirtazapine in pets.

Give this drug to your cat or dog only as directed by your veterinarian, and tell your vet about any other drugs your pet might be taking.

Mirtazapine FAQ

Q: Is mirtazapine addictive at all? Is it connected to the benzodiazapine family of drugs? I do not want to stop mirtazapine because I am sleeping after 15 years of insomnia . Are there any dangerous side effects because for the first time I have no side effects with this drug whereas with every other drug I do . What does this tablet cost to the NHS as I cannot understand why I haven't been given it before.

A: Remeron (mirtazapine) is an inexpensive medication used to treat depression and insomnia by increasing the brain chemicals norepinephrine and serotonin, and by acting on the histamine, alpha, and muscarinic receptors. It is not a benzodiazapine, but as with all antidepressants, the medication should be tapered off when stopping the use of it. Receptors need time to adjust, similarly to other antidepressants. The main side effects include drowsiness (especially at lower doses), dizziness, anxiousness, confusion, increased appetite, increased weight, dry mouth, constipation, nausea and vomiting. This is not a complete list of the side effects associated with Remeron (mirtazapine). For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. When your doctor prescribes a new medication, be sure to discuss all your prescription and over-the-counter drugs, including dietary supplements, vitamins, botanicals, minerals, and herbals, as well as the foods you eat. Always keep a current list of the drugs and supplements you take and review it with your health care providers and your pharmacist. If possible, use one pharmacy for all your prescription medications and over-the-counter products. This allows your pharmacist to keep a complete record of all your prescription drugs and to advise you about drug interactions and side effects. Tell your health-care provider about any negative side effects from prescription drugs. You can also report them to the U.S. Food and Drug Administration by visiting www.fda.gov/medwatch or by calling 1-800-FDA-1088. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Patti Brown, PharmD

Q: What is the best dose for mirtazapine? I need it for an antidepressant effect and insomnia.

A: Remeron (mirtazapine) is a medication that is used to treat depression. It is not entirely clear how this medication works for depression but it is thought it may be due to its actions on serotonin and norepinephrine. These are chemicals used to send messages in between nerves. If serotonin or norepinephrine levels become unbalanced, it can cause a variety of conditions, including depression. This medication helps to balance out those chemicals, which resolves the symptoms of depression. The dose of mirtazapine that a prescriber will choose will vary from patient to patient. The prescribing information on mirtazapine states that the starting dose is 15 mg taken once a day, usually at bedtime. The healthcare provider may increase the dosage if symptoms continue, or decrease the dose if side effects occur. There is not any one dosage that is better than another, it all depends on how your body responds to the medication. The maximum recommended dose of mirtazapine is 45 mg per day. Lori Poulin, PharmD

Q: Can mirtazapine cause joint and muscle aches?

A: Mirtazapine (Remeron) is a medication that is used to treat depression. It is not entirely clear how the medication works, but the drug blocks several different kinds of receptors including serotonin, norepinephrine, histamine and alpha receptors. It is thought that the action of mirtazapine, on serotonin and norepinephrine receptors in the brain, helps relieve the symptoms of depression. According to the prescribing information for mirtazapine, muscle pain was reported as a possible side effect of the medication, occurring in up to five percent of patients taking the medication during clinical studies. There are no documented reports of joint pain as a side effect associated with treatment with mirtazapine. If you suspect that the medication is the cause of your symptoms, you should consult with your physician for further evaluation, diagnosis of the underlying cause and treatment options to help alleviate your symptoms. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Lori Poulin, PharmD

Q: What is the maximum dose of mirtazapine? Can this medication be taken during the day?

A: Remeron (mirtazapine) is a called a tetracyclic antidepressant, which increased certain brain chemicals including serotonin and norepinephrine, and is mainly used to treat depression. It can also help insomnia, but unlike most medications, the low dose causes drowsiness. When the dose is increased, the side effect of drowsiness is decreased. The maximum dose of the medication is 45mg daily. If this dose is not working well for you, your doctor may want to consider adding another medication. It does take approximately one month to get the full effects of antidepressants, so make sure you have given it enough time to work. Other ways to help find depression include exercising, yoga, getting plenty of sleep, improving eating habits, and socializing. Exercise can relax tension in the muscles, relieve stress, and cause the release of hormones and neurotransmitters that are calming and mood enhancing. As little at 10 minutes has been shown to improve mood for at least 2 hours, but 30 minutes a day is recommended. Experts recommend 7 to 9 hours of sleep at night to fight fatigue, which can cause depression. A diet high in fiber and low in fats, such as one filled with vegetables and fruits, can reduce depression. Whole grain foods are better than processed flours and simple sugars. Salmon, herring and other omega-3 fatty acid rich foods have been shown to improve mood. Vitamin B and chromium picolinate can also help. Patti Brown, PharmD

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